Method for cleaning and treating oil and gas wells



R. E. LEE.

Dec. 19, 1922.

METHOD FOR CLEANTNG AND TREATING OIL AND GAS WELLS.

2 SHEETS-SHEET l FILED JUNE I8, 1921.

all/1 9 lvwemtoz fQo Aer'f L 5%., M 9 QZWZ/ R. E. LEE.

Dec. 19, 1922.

METHOD FOR CLEANING AND TREATING OIL AND GAS WELLS.

2 SHEETS-$HEET 2- HLED JUNE 18, l92l.

gmmtoc Robe/7 E L663 L QGLNJC Patented Dec. 19, EQZZQ urea stares Masses ROBERT E. LEE, OF FORT WORTH, TEXAS.

METHOD FOR CLEANING AIBTD TREATING OIL AND GAS WELLS.

Application filed June 18, 1921. Serial No. 478,540.

ing and Treating Oil and Gas Wells; and I chamber.

dohereb'y declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings forming part of this specification.

This invention relates to a method and "apparatus for cleaning, agitating, and otherwise treating oil and gas wells by means of moist steam, the object being to start or increase the production of oil or gas from the well. The principal object of the present invention is to provide a method of treating such a well by means of moist steam, utilizing the steam not only for cleaning the well but for hermetically sealing the lower part of the casing.

A second object of the invention is to provide apparatus which will'enable one to control the pressure in the sealing chamber at the bottom of the casing and be able to control, from a point above the ground, the pressure'in the well below the expansible sealing The prewure and temperature of the steam to be used in cleaning a well may be determined by a scientifically conducted testof the tectonic structure which test contemplates not only the microscopic examination 'to determine porosity and texture of the specimens taken from the bottom of the well, by which term is meant the formations in which the oil or gas is stored and which is ordinarily found at the bottom of the longest string of casing in the well, but also a chemical analysis 'of the above mentioned earthy specimens so as to determine the nature and the ratio ofthe component parts many years and it is customary in all such 1 of the formation, and in these examinations the steam pressure and temperature best adapted for the most successful results may readilybe calculated-by one skilled in the art, such calculations forming no part of the present invention, the usual steam pressure ranging from 125300 lbs. at a temperature of 340-6359 F.

Wells have been cleaned with steam for cases to hermetically seal the well at some place, preferablynear the bottom of the casing. It is also believed to be new in this art to pass live steam into a pressure chamber and to allow it to escape into the well to be treated so as to thoroughly clean the well of sediments of the heavier parafiin series of hydrocarbons which will be melted and taken in solution b the process herein described.

To success ully accomplish the desired results (which are the thorough cleaning of the voids or porous spaces and fissures of all soluble matter or sediment, such as paraffin wax, melted and taken in -solution by the circulating medium which is steam under pressure and carried to surface or top of well, by and in said circulating steam under pressure up through a return lead steam pipe, thereby thoroughly cleaning and carrying to surface all soluble residue accumulated in the voids or porous spaces of the oil or gas producing horizons 10 and the agitation' of the tectonic structure of the oil or gas producing horizons 10. by expansion due to hea.tmoist heat such as steam is prefi erable, because dry heat such as electrical heat, bakes all the soluble substances accumulated in horizons 10 into the tectonic structure of the minute voids, thereby clogging' up the porous spaces which'are connected in common from the center of the well, outwardly in radial-circles, which reduces the area and extent of the porous spaces or voids in direct proportion to theamount of clogging effected by dry heat which sets up increased electronic vibrations or moleculan action) the medium must of necessity be circulated under pressure thoroughly throughout the entire oil or gas producing horizons 10, co-extensively with the voids or porous spaces and fissures connecting each with the other, beginning from the center of the well and extending outwardly in radial circles from the center to the furthermost regions connected. in common, thereby effecting a continuous avenue of porosity from the well center outward in radial circles to the furthermost regions pos-, slble to recover 011 or gas from in horizons meate horizons 10 and absolutely cannot take,

Gil

as I 1,439,560

in solution the soluble substances and carry the same in it to the surface or top of well, and any results short of accomplishing the above is but a temporary benefit at best, and in most casesis a detriment to the well or wells treated, the object being to aid or increase the production of oil or gas, or both, from the well or wellsthus treated.

In the drawings accompanying the spec1- fication l have shown somewhat diagrammatica-lly an apparatus which furnishes a convenient method of practicing this process of treatment of an oil well. In such illustrations Figure 1 is a central section through such portion of piping at the top of the well as is above the surface of the ground.

Fig. 2 is a vertical central section at the bottom of the well showing particularly the pressure chamber.

Fig. 3 is a horizontal section through the center of the pressure chamber before the latter is expanded to hermetically seal the bottom of the well- Fig. 4 is a central sectional view through one of the automatic spring valves.

Live steam from the dome of the boiler (not shown). is conducted through a horizontal pipe 14, having therein a gate valve 15, to a coupling 16 to the lower end of which is secured the main live steam pipe 17, preferably of somewhat larger diameter than the pipe 14 since the live steam space in the main pipe 17 is the annular space between such pipe and the return pipe 18 concentric therewith, which passes through the coupling 16 in a non-leaking joint formed by use of packing 19 held in place by a thimble 20 of usual type. The pipe 17 passes through the cap 22 of the casing 23 and extends to a point at or near the bottom of the well casing where it is threaded to the upper head 25 of a cylindrical member denoted as a whole as the pressure chamber 26, this chamber being formed of the upper head 25 threaded to receive the main live steam pipe 17 and a similar lower head 28 forming a steam tight joint with the return pipe 18 and a hollow perforated steel cylinder 29 forming the cylindrical surface of the pressure chamber and serving to hold in place the asbestos packer 30 which is interlined with rubberized cotton fabric 31, preferably about one-quarter of an inch thick for an average sized casing.

A plurality of bolts 32, preferably four in-number, pass through the two heads so that the asbestos packer 30 may be securely held in position in the annular grooves 33 and 34 of the heads by tightening the bolts 36. As previously stated, the steel cylinder 29, which may be a section of a casing, is perforated by holes 37 bored in the cylinder and spaced about two inches apart center to center when half-inch holes are used. When live steam is conducted to the pressure chamber 26 through pipe 17, the pressure of the steam passes through the holes 37 and acts against the inner surface of the packer 30 and causes it to assume a barrel shape so as to entirely close the casing 23.

A plurality of relief valves 40 are threaded into the lower head 28, these valves being of the usual type having a conical valve member 41 held against its seat 42 by means of a helical spring 43 engaging against a sleeve 44 loosely mounted in the cap 45, the latter being threaded to the valve body so that by turning the cap the tension on the spring may be adjusted to any pressure desired and when so adjusted the cap may be secured in position by means of the locking nut VVheni so adjusted the valve 41 will remain sea-ted until the predetermined pressure has been reached at which time it will open against the pressure of spring 43 and will discharge the live steam from the pressure chamber 26 through the out-let 48 to the well hole 50 from whence it will pass through the oil producing strata or horizons 10 where it will not only agitate the structure in the oil and gas producing strata by causing expansion of the forma tion, but will increase the voids or porous spaces and will consequently loosen the parafiin base sediments or other waxy substances that may have accumulated in these voids or fissures, either through filtration,

evaporation or other sources, and the steam, being in vapor form and moist, will break down these higher hydrocarbons and will assimulate or absorb them in vapor form.

The return pipe 18 is perforated at its lower end with small bored openings 51 preferably about one-quarter inch in diameter and fairly close together and is protected at its extreme bottom by a steel spider 52 or by a similar protective element. This return pipe 18 delivers to the top of the well all the soluble residue that the steam vapor has thus absorbed or assimulated in passing through the formations at the bottom of the well, thus cleaning the well and sufficiently agitating the oil and gas producing strata or horizons so that the oil will begin to precipitate and follow the line of least resistance which will be the cleaned and now emptied voids and fissures, the common center of which is the center of the well casing at the bottom of the hole 50.

The pressure in the pressure chamber 26 is regulated by setting the valves 40 to such pressure as will insure the hermetic sealing of the well. Care should be taken that the pressure in the space 50 is always appreclably lower than the pressure necessary to seal the lower portion of the casing. This is conveniently accomplished by installing a steam pressure gage 54 and thermometer 55 in the upper portion of the pipe 18 and by providing an automatic spring loaded through the pressure chamber and in the well.

What I claim is 1. The process of treating a gas or oil well which consists in passing a heated medium under pressure to the oil or gas formations to be treated and in returning said heated medium through said well, and in utilizing the pressure of said medium to seal the well at a point near the gas or oil producing formations. I I

2. The process of treating a gas or oil well which consists in passing moist steam through the well casing down to the formations to be treated and in returning the spent steam through said casing, and in utilizing the pressure of said, steam to seal the casing at a point near its bottom.

.3. The process of treating a gas or oil well which consists in passing a heated medium under pressure to the oil or gas for-.

' mations to be treated, returning said heated medium through the Well,sealing the well at a point near the gas or oil producing formations and in maintaining the pressure below said seal lower than the pressure exerted against the sealing means.

4. The process of treating a gas or oil well which consists in passing moist steam through the well casing down to the formations to be treated, returning the spent" steam through the casing utilizing the-pressure of the moist steam to seal the casing and in manually controlling the pressure of said steam below the seal at a pressure belowthe pressure used in sealing the casing,

whereby a continuous circulation of steam through the casing and below the seal is provided. V

5. The process of treating a gas or oil well .which consists in passing moist steam through the well casing to the formations to be treated utilizing the pressure of said moist steam to seal the casing at a point above said formations, passing said steam below said seal to said formations to .dis

solve and vaporize the heavier p araffins,

at a pressure in excess of 125 pounds and at a temperature in excess of 340 F. to the gas or oil formations to be treated in order to clean such formations of paraflin base sediment and other waxy substances, and in returning the spent steam laden With such sediments and substances through the well opening.

7. In an apparatus of the type described, an expansible pressure chamber adapted to hermetically seal a well, means for supplying fluid under pressure to said chamber, means for discharging said fluid from said chamber when the pressure in said chamber exceeds a predetermined figure, means for conveying fluid through said chamber, and

means for controlling the pressure in said last-mentioned means.

8. .An apparatus of the type described, an expansible chamber, means to supply fluid under pressure to said chamber toseal a well, and a valve in the lower end of said chamber to discharge fluid from said chamher when a ceeded.

9. An expansible chamber, means to supply fluid under pressure to said chamber to seal a well, and an adjustable valve in the lower end of said chamber to discharge fluid in said chamber when the predetermined pressure at which said valve is adjusted is exceeded- 10. A pressure chamber consisting of' a predetermined pressure is expair of-circular heads, a perforated cylinder between said heads, a packer surrounding said cylinder, a pipe leading to one of said heads, and a ,second pipe within said first mentioned pipe and passing through the second head. i

11. A pressure chamber consisting in a closed cylinder, a relief valve mounted in the lower end of said cylinder, means for conveying pressure to said cylinder, means for conveying pressure through said cylinder, and mechanism for indicating the pressure in said lastmentioned means.

12.. In a well packer, an expansible cylindrica'l member, means fordelivering fluid under pressure to said cylinder to expand same against the inner surface of a well.

casing, means for discharging fluid in the interior-of said cylinder to the lower portion of the well, and means passing within said fluid delivering means and extending below said cylinder for conductin fluid from the bottom of the well to t e top thereof. I

ROBE-RT E. LEE. 

